[Fedora-xen] backup domU

[Aaron Metzger]

Mathieu Kretchner wrote:

> Do you have good how to about backup a LV ? and creating a domU in an LV ?
> 


Google for "LVM2 snapshot" or look at the "snapshot" option on the man
page for "lvcreate" to answer the first half of your question.

Here is a snippet of the cron script that I run twice a day to backup
all of my guests while they are running.

> /usr/sbin/lvcreate --extents 100%FREE --snapshot --name vmsnapshots /dev/vms/vms
> /bin/mount /dev/vms/vmsnapshots /vmsnapshots
> DAY="`date +%A-%H%M`"
> /usr/bin/time --format "%E" /bin/tar --sparse -zcvf /mnt/ssbackup01/vms-$DAY.tar.gz /var/lib/xend/domains /vmsnapshots
> /bin/umount /vmsnapshots
> /usr/sbin/lvremove --force /dev/vms/vmsnapshots

I am also interested in seeing a detailed howto for the "creating a domU
in an LV" part of your question.  I currently do live backups of all of
my virtual machines using LVM2 snapshots but I had to put my virtual
machine images in files instead of partitions to accomplish this.  I
never successfully created a virtual machine in an a logical volume
partition.  Some people say that I am sacrificing performance by putting
my virtual machines in files.  If that is true, then I'd love to see a
detailed example of creating an arbitrary Xen guest image in a a logical
volume.

--
Good luck,
Aaron Metzger